Just got a Mac Pro in a trade for my 2011 MBP I5. My current Mac Pro set up is 2 x 2.66ghz dual core Xenon with 24gb of ddr3 at 1066mhz. I am deciding between a 2 x 6 core 2.93ghz X5670 CPU's (which I can acquire a pair for around $115) or 2 x 4 core X5677 CPU's running at a 3.46 ghz for around the same price. I'm trying to decide if the 8 core with the higher 3.46 ghz or the 12 core @ 2.93 ghz would be better. I am looking to future proof this machine as much as possible. Any facts or opinions would help my decision. Looking to spend under $125 on a pair of CPU's, hence why I chose the 2.93ghz x5670. Oh, and my machine was just firmware updated to 5.1, so it does support 2 x 6 core cpus. Thanks in advance!